JPS59124163A - Semiconductor element - Google Patents

Abstract

PURPOSE:To obtain a semiconductor element characterized by excellent electric characteristics and small aging value, with a good yield rate, by using a thin Si.Ge film, which includes H atoms of 3 atom % or less. CONSTITUTION:On a glass plate 101, e.g., SiH4 and GeH2 are dilluted by H2 or the like and reacted in a specified deivce, and a thin polycrystal Si.Ge film 102 is formed. Source and drain electrodes 103 and 104 are provided through insulating films 107 and 108. The surface is coated by an insulating film 105. A gate electrode 106 is attached. Thus a typical thin film FET is formed. In this case, the H atoms included in the thin film 102 are mainly pesent in the gain boundary of the polycrystal Si.Ge. When the quantity of the H is large, the H is included in the double or triple bond or in a free state. The characteristics of the element are deteriorated by said H in the unstable state. When the quantity of H inclusion in the thin film is restricted to 0.01-3 atom%, optimally to 0.1-1 atom %, ageing is reduced, the characteristics are excellent, dispersion is reduced, and the yield rate is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device such as a field effect transistor, and more particularly to a semiconductor device whose main portion is composed of a polycrystalline silicon germanium thin film semiconductor layer.

Recently, the scanning circuit section or liquid crystal (hereinafter referred to as FLC) of image reading devices such as elongated one-dimensional photosensors and large-area two-dimensional photosensors for image reading has been developed.
With the increase in the size of these devices, the drive circuits of image display devices that use ``FJiliO'', electroluminescence (hereinafter referred to as FF1L), and electrochromic materials (hereinafter referred to as FJiliO) are being made using silicon formed on a predetermined substrate. It has been proposed to form a thin film as a material. Conventionally, attempts have been made to use hydrogenated amorphous silicon thin films and polycrystalline silicon thin films as silicon thin films. Of course, the effective carrier mobility (hereinafter referred to as Fμoff) required by the scanning circuit section of a high-speed, high-performance reading device or the drive circuit of an image display device is about 50 to 100 cz2/V-sec.
Thin film transistor (TPT) using amorphous silicon thin film
), μeff is about 0. I C”m2/V;sec
Because of its small size, it could not necessarily be said to be suitable for constructing the above circuit section. On the other hand, polycrystalline silicon thin films have a smaller μ than amorphous silicon thin films. Although ff is large, an annealing process is required to meet the above requirements, which causes problems such as the process becomes complicated and a uniform film may not be obtained over a large area.

On the other hand, the formation of polycrystalline germanium thin films has conventionally been attempted by vacuum evaporation, and the hole mobility (hereinafter referred to as μ■) of the film obtained by this method is extremely large, several hundred cm2/V・8θC, and μeff is also low. Big things were expected. However, because a polycrystalline germanium thin film normally forms a high concentration of acceptor levels, controllability to n-type or p-type semiconductors is poor, and polycrystalline germanium thin-film semiconductor devices have not been put to practical use. . This is because it is difficult to form a so-called intrinsic semiconductor, and the efficiency of doping the germanium matrix by adding impurities is extremely low.

In addition, the germanium thin film undergoes thermal conversion (thermal conversion, which converts an n-type semiconductor into a p-type semiconductor by heat treatment).
Since a phenomenon called 1 Conversion was observed, it was unsuitable for device fabrication involving a heat treatment process.

As described above, the current situation is that conventionally produced elements or devices made of polycrystalline germanium thin films have not been able to sufficiently exhibit desired characteristics and reliability.

In addition, germanium has a smaller energy gap than silicon, so for example, the reverse saturation current of pn junctions, which are often used in semiconductor devices, may be large and cause problems, and if the energy gap is small, the valence band However, the carrier concentration raised by thermal energy in the conductor approaches the carrier concentration provided by impurities at low temperatures, resulting in a narrow temperature tolerance range for devices.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor device with high device performance and high reliability. In addition, a semiconductor using a polycrystalline silicon/germanium thin film has extremely few impurity levels in the forbidden band of the semiconductor, that is, the doping efficiency of the impurity addition to be controlled is extremely good, and the energy gap is comparable to that of germanium. The purpose is to provide devices. Furthermore, it is an object of the present invention to provide a field-effect thin film transistor with high performance, high reliability, and good stability by using a polycrystalline silicon germanium thin film medium conductor layer formed on a substrate. Another object of the present invention is to provide a large-area semiconductor device whose constituent elements are field-effect thin film transistors using an excellent polycrystalline silicon germanium semiconductor layer.

The semiconductor device of the present invention for achieving this purpose is 3a.
It is characterized in that its main portion is composed of a polycrystalline silicon germanium semiconductor layer containing more than 10% of hydrogen atoms.

Semiconductor devices manufactured using polycrystalline silicon/germanium thin films containing the above-mentioned amount of hydrogen atoms have good electrical characteristics, do not change over time, and can significantly improve device yield and variation. can. For that reason, LC.

It is possible to stably provide a display using EL or GC, or a scanning circuit, a driving circuit, etc. of an image device, etc.

A field effect thin film transistor (TPT) as an example of a semiconductor device made using the polycrystalline silicon germanium thin film of the present invention as a material, a semiconductor layer, an electrode layer,
It is known as a transistor using an insulating layer. Namely 1. A voltage is applied between the source and drain electrodes that have ohmic contacts adjacent to the semiconductor layer, and the channel current flowing there is modulated by the bias voltage applied to the gate electrode provided through the insulating layer.

FIG. 1 shows an example of the typical basic structure of such a TPT. A source electrode 103 and a drain electrode 104 are provided on and in contact with a semiconductor layer 102 provided on an insulating substrate 101, and an insulating layer 105 is formed to cover these.
is provided, and a gate electrode 106 is provided on the insulating layer 105.

TIi′ having the structure shown in FIG. 1 according to the present invention
In T, the semiconductor layer 102 is composed of a polycrystalline germanium thin film having the above-mentioned characteristics.
A first n+ layer 107 and a second 1 layer 108 are provided between each of the two electrodes, ie, the source electrode 103 and the drain electrode 104, to form an ohmic contact.

The insulating layer 105 is formed by CVD (Chemical Vapor
rDeposition), LPOVD (Lovr
Presure C! chemical vapor
Deposition) % or PC! VD (Pla
scoaC! chemical vapor depot
siliconite 2-ide formed by
It is made of materials such as S10□ and Al2O3.

The reactive gas used to create the polycrystalline silicon germanium thin film constituting the semiconductor layer 102 is a substance whose constituent atoms are silicon, such as monosilane (s1n4),
Silane gas such as disilane (Si2H6) and substances containing germanium as constituent atoms, such as monogermane (G
Examples include germane gases such as eH4), digelma/(Ge2Hb), and trigermane (ie, H8), and these reactive gases can also be used after being diluted with a gas such as H2+Ar+H8.

Field-effect TPTs are classified into types with a gate insulating layer on the gate electrode (upper gate type) and types with a gate electrode on the gate insulator (upper gate type).On the other hand, the source and drain electrodes have an insulating layer. The type (Copla) at the interface between the semiconductor layer and the semiconductor layer
It is well known that there are four types for each combination. The structure shown in Figure 1 is the upper gate 0o
Although an example that is classified as p1ar 9 field effect type 'I'FT has been shown, it goes without saying that the field effect type TPT according to the present invention may be any of these.

In the present invention, the lower limit of the amount of hydrogen atoms contained in the polycrystalline silicon germanium thin film constituting the semiconductor layer, which is the main part of the semiconductor element, is preferably 0.01 atomic.
Various transistor characteristics can be improved by using a 1-at (hereinafter referred to as 1-at). On the other hand, the hydrogen atoms contained in the polycrystalline silicon/germanium thin film mainly exist at the grain boundaries of the polycrystalline silicon/germanium and are bonded in the form of 81-R, Ge-H.
If the amount of hydrogen atoms contained is large, 5i = -H2, Si Mihe.

It is expected that hydrogen is contained in bonded forms such as Ge-H2, Ge-H3, or in a free state, and the transistor characteristics that are thought to be caused by hydrogen contained in these unstable states. Deterioration often occurs.

The inventors have found from many experiments that when the amount of hydrogen contained in the polycrystalline silicon germanium thin film is 5at.% or less, there is almost no deterioration of the transistor characteristics, and the characteristics are stably maintained. It turns out that you can get it.

Further, the amount of hydrogen atoms contained in the thin film is 5 at.

When the transistor is continuously operated in the case where the voltage exceeds 1, a decrease in μθff is observed, and the output drain current decreases with time, and the threshold voltage VTH decreases. Changes over time have been observed. Therefore, in the present invention, the amount of hydrogen atoms contained in the polycrystalline silicon germanium thin film that constitutes the main part of the semiconductor device is preferably 0.01 to
3 at, more preferably 0.05 to 2 at.

The optimum range is 0.1 to 1 at.%.

The measurement of the amount of hydrogen atoms contained in the polycrystalline silicon germanium thin film specified in the present invention is 0.1 at
, 4 or more is usually used in chemical analysis, and the elementary weight was measured using a tail hydrogen analyzer (Model 1 manufactured by Perkin Elmer), and the amount of hydrogen atoms contained in the film was calculated using an atomic coefficient.

Micro-quantity analysis of 0.1 at, % or less is performed using a secondary ion mass spectrometer - 8-MS
-6f) KeV, sample current s x
10-” A % spot size is 50 μm in diameter, etching area is 250×250 μm, S1+ and ()
The detection intensity ratio of r ions to e+ was determined, and the hydrogen atom content was calculated in at;omic-%.

In order to demonstrate the effects of the present invention, the following method was used to measure changes over time in polycrystalline silicon germanium thin film transistors.

First, a TPT having the structure shown in FIG.
1, a gate voltage V of 40V1 and a drain voltage VD of 40V is applied between the source 203 and the drain 202, and the drain current flowing between the source 203 and the drain 202 is measured using an electrometer (Keithley).
6100 electrometer). The rate of change over time was expressed by dividing the amount of variation in drain current after 500 hours of continuous operation by the initial drain current and multiplying it by 100.

The threshold voltage (VTH) of TFT is MOS-FjET (M
etal-oxlae-8emiconauctor
vDv, which is normally carried out in
”; Defined by the point where the straight line part of the curve is extrapolated and intersects the horizontal axis ■D-axis. V before and after the change over time
The value of TH was also checked at the same time, and the amount of change (ΔVTH) was expressed as a voltage.

Various methods can be used to control the amount of hydrogen contained in the formed polycrystalline silicon germanium thin film semiconductor layer to the above-mentioned amount.

For example, silicon hydride such as SiH4+ Si2 H6 and germanium hydride such as GeH4, Ge2H6 are precipitated by glow discharge decomposition method (()D method), or in a gas containing H2 or GeH4 using Gθ met. A method of evaporating - using an electron beam or the like in an H2 plasma atmosphere (F method),
This can be performed by a method of vapor deposition in an H2 atmosphere at an ultra-high vacuum (H'7D method), a method of treating a polycrystalline silicon germanium thin film formed by OVD or LPOVD with H2 plasma, and the like.

As disclosed in the present invention, a thin film with a substrate surface temperature of 500 can be formed by the GD method, sp method, p method, and HVD method. This is advantageous in that the substrate can be heated uniformly and inexpensive large-area substrate materials can be used when creating large-area drive circuits and scanning circuits for large-area devices. . Furthermore, it is important as it meets the demand for the use of translucent glass substrates in applications of image devices such as substrates for transmissive plate-claw elements and substrates for substrate-side incident photoelectric conversion elements. be.

That is, according to the present invention, a low temperature region can be used to obtain a desired polycrystalline silicon germanium thin film.
In addition to heat-resistant glasses such as high-melting point glass and hard glass, heat-resistant ceramics, sapphire, spinel, silicone urethane, etc., general low-melting point glasses, heat-resistant plastics, etc. may also be used. Glass substrates using general low-melting point glass include ordinary glass with a softening point of 630C, ordinary hard glass with a softening point of 78DC, and ultra-hard glass (5181 class ultra-hard glass) with a softening point of 820t''. It is possible to use it.

In the manufacturing method of the present invention, the temperature of the substrate can be kept below the softening point no matter which substrate is used, so there is an advantage that the film can be formed without damaging the substrate.

In the embodiments of the present invention, Corning +
Although 7059 glass (manufactured by Corning Inc.) was used, quartz glass or the like having a softening point of 1500'c can also be used as the substrate. However, from a practical point of view, it is advantageous to use ordinary glass at low cost and to produce thin film transistors (TPT) over a large area.

Hereinafter, in order to explain the present invention in more detail, the process from forming a polycrystalline silicon germanium thin film to the fabrication process of TPT and the results of TPT operation will be specifically explained using examples.

Example 1 In this example, a polycrystalline silicon germanium thin film was formed on a substrate to create a TPT, and an apparatus as shown in FIG. 3 was used.

As the substrate 300, Corning +7059 glass was used.

First, after cleaning the substrate 300, HFIH1 (0,10H3
After lightly etching the surface with a mixed solution of 000H and drying it, it was placed in a Pelger vacuum deposition chamber (hereinafter referred to as Pelger).
Substrate heating holter 302 placed on the anode side in 601
It was installed on. Then, attach the Pelger 301 to the diffusion pump 3.
09 and background pressure 1 X i O'Torr
Exhaust was carried out to the end. If the pressure at this time is high, not only will the reactive gas not contribute effectively to film deposition, but also oxygen and nitrogen will be mixed into the film, which will significantly change the resistance of the film, which is not desirable. Next, raise the substrate temperature TS and heat the substrate 600.
The temperature was maintained at 500C. Also, the substrate temperature is measured by thermocouple 6.
It was monitored on 06.

The reactive gas introduced in this example was SiH4 gas (hereinafter referred to as 5in4(1)/H
2) and GeH4 gas (hereinafter referred to as G8H4(1)/'H
2) and H2 gas at 100 volume ppm
B2 diluted to (hereinafter referred to as vojl!, ppm)
Using H6 gas (hereinafter referred to as B2H6(100)/H2), 51a4(1)/''2 was converted to 40 BCCM using a mass flow controller 310, 'GeI(4(
1)/H2 using a mass flow controller 604 with a flow rate of 20800M, and further B2H6 (100)/H2
3 using mass flow controller 307, OS
The OCM was combined with the flow rate and introduced into the Pel jar 301 from the ring-shaped gas outlet 615, the main pulp 617 was adjusted, and the pressure inside the Pel jar 301 was set to 0.01 Torr using the absolute pressure gauge 316.

After the pressure inside the Pelger 301 stabilizes, 1! is applied to the cathode electrode 314. +, 56 MH, high frequency electric field from power supply 6
15 to start glow discharge.

At this time, the voltage was 0.6, the current was 55 mA, R
F (Radis Frequency) power is 20W
Met.

The thickness of the formed film was 0.5 μm, and its uniformity was 0.2 at.% when a circular ring-shaped outlet was used.

Next, using this film as a material, TPT was fabricated according to the steps outlined in FIG. 4. As shown in step (a), after depositing the polycrystalline silicon germanium thin film formed as described above on the glass substrate 300, it was heated with hydrogen gas for 10 minutes.
pH, gas diluted to 0 voJ, ppm (hereinafter p,
H, (100)/H2) is Gea4 and EliH
The gases were flowed into the Pel Jar 301 at a molar ratio of 5 x io-3 to the total amount of the four gases, and the pressure inside the Pel Jar 301 was adjusted to 0.12 Torr to perform glow discharge. A single layer 402 doped with phosphorus was formed to a thickness of 0.05μ (step (b)).

Next, as shown in step (C), photo-etching (with 2 layers 4
02 in the region of the source electrode 406 and the drain electrode 404
removed except for the area. Next, in order to form a gate insulating film, the above-mentioned substrate was again mounted on the heating holder 302 on the anode side inside the Pelger 501. Polycrystalline silicon・
Pelger 6 as in the case of producing a germanium thin film.
01 is exhausted, the substrate temperature Ts is set to 250C, and NH3 gas with a purity of about 100% is mass flow controlled -3
20 SOCM in 05, 10 vol, % in H2
S:LH4 (hereinafter S:LH4(1o)/
(denoted as H2) was set to 5 with Massonro control 7-308.
The 5iNH film 405 was deposited to a thickness of 0.25 μm by introducing the 5iNH film 405 to a thickness of 0.25 μm by introducing the 5iNH film 405 to a thickness of 0.25 μm by controlling the introduction of the 5iNH film 405 to a thickness of 800M and generating a glow discharge (step (d)).

Next, a contact hole 406-1 for the source electrode 406 and drain electrode 404' is formed by a photo-etching process.
, 406-2 (step (e)), then 5iN
AJ on the entire surface of H film 405? After forming the electrode film 407 by vapor deposition (step (f)), the stain electrode film 407 is processed by a photo-etching process to form the source electrode extraction electrode 4.
08, a drain electrode extraction electrode 409 and a gate electrode 410 were formed (step (g)). After that, heat treatment was performed at 250C in an I12 atmosphere.

The TPT (channel length L: 20μ, channel width W=650μ) formed according to the above conditions and steps showed stable and good characteristics.

FIG. 8 shows an example of the VD- characteristic curve of the TFT prototyped in this manner. As shown in Figure 8, vG=10V (
7),! : When Iv = 6.8 x 10'A, S, and vG = Q7, the voltage was 4 x 10-8A, and the threshold voltage was 5.7V. Also, usually MO8, TPT
The μeff determined from the straight line portion of the vG-convex curve used in the device was 55L1rL2/V, Bec, and a TPT with good transistor characteristics capable of forming various drive circuits with high mobility was obtained.

In order to investigate the stability of this TPT, we continuously applied 40V of DC' pressure to the gate and measured the change in torque over a period of 1000 hours.There was no change in twist, and T' Change in threshold voltage before and after FT change over time ΔVT
There was no H, and the stability of TPT was extremely good. In addition, the TFT characteristics after aging change from VD- + vG-, etc., the measurement results are unchanged from before the aging change measurement, and 1 μeff is 55.
It was the same as Cm2/■, 8eC.

As shown in this example, the TPT whose main part was composed of a polycrystalline silicon germanium thin film containing 0.2 at.% hydrogen atoms was found to be an extremely high performance transistor.

Example 2 RF/<war 40y
, 5i-H4(1)/H2 flow rate 40 Sec! M
, GeH4(1)/H2 flow rate 201EOc! M,
A polycrystalline silicon germanium film was formed on a Vycor glass substrate under conditions of a flow rate of B2H6(1oo)/H2 of 30 SOOM, a pressure of Q, and Q 2 Torr. The substrate temperature was set at intervals of 50c over a range of 200 to 700υ, and the film thickness was 0.5μ. Then, the amount of hydrogen atoms in each polycrystalline silicon germanium film was measured,
Also, μ of each of TPT (sample layers 1-1 to 1-11) prepared by the same method as in Example 1 using these prepared films. ff is shown in Table 1.

As can be seen from Table 1, those with a hydrogen atomic weight of more than 3at.% or less than CLO1at.% have a μeff of 10.
0 cm2/V, eec or less, ■D change over time and ΔVTH are relatively large, and the stability of characteristics is also poor.

Example 3 Next, Example 3 will be explained in detail with reference to FIG.

First, Corning 47os prepared in the same manner as in Example 1
q Substrate holder 50 in a vacuum chamber 501 that can reduce the pressure of the glass substrate 500 to 2×10” Torr
2, the pressure inside the vacuum chamber 501 is 4 x 10''
After reducing the pressure until the pressure is below jorr, the heater 50
6, the substrate temperature was set at 500υ. Next, the electron gun 504 is operated at an accelerating voltage of 10 V to irradiate the silicon evaporator 505 with the emitted electron beam, and the electron gun 504' is further operated at an accelerating voltage of 10 V to emit the electron beam. The germanium evaporator 505' is irradiated with an electron beam, and then the Knudsen cell 509 is heated with a heater.
511 to evaporate boron 510 from the Knudsen cell 509, and open the shutters 512, 507 and 507' to form a film thickness of 0.5μ on the substrate 500 using a crystal resonator film thickness gauge 506. A polycrystalline silicon germanium film was formed under controlled conditions.

The pressure during vapor deposition at this time was 1.5×10 Torr
s deposition rate was 1.4 A/sea.

The sample thus obtained is designated as sample 3-1.

Next, a similarly prepared Corning +7059 glass substrate 500 is fixed to the substrate holder 502, and the stem is placed in the bath 501.
After reducing the pressure inside the tank to a pressure of 4 x 10” TorrJ2J,'f, high-purity hydrogen gas (99,9
99%) was introduced into the vacuum chamber 501 by the variable leak valve 508, and the pressure inside the chamber was increased to 2 x 10' Torr.
After setting the temperature to r, the substrate temperature was set to 500 μm, and silicon germanium and boron were evaporated to form a film in the same manner as in the case of creating sample 3-1. At that time, the film formation rate was 1,4
A polycrystalline silicon/germanium film with a thickness of 0.5 μm was formed by controlling the temperature to be X/sθC. The sample thus obtained is designated as sample 3-2.

The amount of hydrogen contained in the polycrystalline silicon germanium thin film was measured for each of Samples 6-1 and 3-2, and TPT was prepared using the same method as in Example 1 using each sample.
Table 2 shows the results of the change over time in μeff*ID and the amount of change in threshold voltage AvTH measured for each of the above.

As shown in Table 2, the amount of hydrogen contained in the polycrystalline silicon germanium thin film is (Lo, 1.at
, less than 1, and sample 3-2 contained 0.3 at.

For this reason, the effective carrier mobility μθ of the fabricated TPT is
ff is larger in sample 3-2 than in sample 3-1, and TPT
Sample 3-2 also had better stability, and was found to be preferable as a chihiromorphic layer for TFT.

Table 2 Example 4 A TPT fabricated using a polycrystalline silicon germanium thin film fabricated using the ion blasting deposition apparatus according to the present invention shown in FIG. 6 will be described in detail.

First, a polycrystalline silicon germanium silicon evaporator 406 is placed in a boat 607 in a deposition chamber 603 that can be depressurized, a germanium evaporator 606' is placed in a boat 607', and a Corning +7059 glass substrate is placed in a support 611.
-1,611-2, and the pressure inside the deposition chamber 603 is approximately I
After exhausting until the pressure reached X 10-' Torr, H2 gas with a purity of 99.999 cm was introduced into the deposition chamber 603 through the gas introduction pipe 605 so that the hydrogen partial pressure pH became 1'X 10' Torr. Gas introduction pipe used 60
No. 5 used a gas outlet in which two holes with a diameter of 0.5 mm were opened at an interval of 2 meters in a loop-shaped portion at the end of the inner diameter.

Next, apply 1!1.51s to the high frequency coil 610 (diameter 5 degrees).
A high frequency MH2 wave was applied with an output of 200 W to form a Takaoka Hagusma atmosphere inside the high frequency coil 610.

Further, while the supports 611-1 and 611-2 were being rotated, the heating device 612 was activated to heat the Gazis substrate to 450C.

Next, silicon evaporator 606 and germanium evaporator 606
The silicon and germanium were heated by irradiating electron beams from electroguns 608 and 60B', respectively, and the silicon particles and germanium particles were made to fly. In this way, a film of polycrystalline silicon germanium was formed to a thickness of about 0.5 μm, and using this film, a TPT was fabricated in the same steps as in Example 1 (Sample 4-1). In addition, in the process of forming a polycrystalline silicon/germanium thin film, the film was formed without introducing hydrogen, and T
PT was produced (Samples 4-2).

μf3 measured for each of the samples prepared in this way
ff + ID change over time, threshold voltage change amount ΔVTH
The results are shown in Table 3.

As can be seen from Table 3, sample 5-1 showed no change in temperature over time, and exhibited good transistor characteristics with μeff of 32 crIL2/V-8.

Table 3 Example 5 Next, an example in which a polycrystalline silicon germanium thin film was formed by sputtering will be described in detail with reference to FIG.

A Corning≠7059 glass substrate 700 prepared in the same manner as in Example 1 was fixed in close contact with the substrate heating holder 702 on the upper anode side in the Pelger 701, and placed on the electrode plate of the f section cathode 706 so as to face the substrate. A polycrystalline silicon plate (not shown; purity 99.999%) and a polycrystalline germanium plate (not shown, 99.999%) are placed on the electrode plate of the lower cathode 707 to face the substrate.
was installed. The internal pressure of Pelger 701 is 1×10'To
Evacuate with the diffusion pump 709 until the temperature reaches rr, and heat the substrate heating holder 702 to raise the surface temperature of the substrate 700 to
I kept it at υ.

B2H6(100)/[(2 gas is supplied by mass flow controller 716 at a flow rate of 5 can, and H
Mass flow control of gas - 0 terrorist attacks due to 714
The gas is introduced into the Pel jar 701 through the annular gas introduction pipe 712 at a flow rate of SC (!
．． 01 Tour.

After the Pelger internal pressure stabilizes, the lower cathode electrode 70
A high frequency electric field of 1156 MH2 was applied to the lower cathode electrode 70 at a voltage of 5.5 KV by the power source 708.
A high frequency electric field of 15.56 MH2 is applied to the can and do electrodes 706 by applying a voltage of 2.5 to the power source 709.
, 707 and the anode (substrate heating holder) 702, a p-type polycrystalline silicon/germanium thin film was deposited on the glass substrate 700. The thickness of the film formed at this time was 0.55μ. Further, the amount of hydrogen atoms contained in the polycrystalline silicon germanium thin film formed at this time was 1.6 at.

μ of TPT produced by the same method as in Example 1 using the obtained sample. ff is 35c11L2/V, 6θ.

The change in shame over time is less than 0.1%, and the change in threshold voltage is ΔV.
T exhibits stable and good transistor characteristics with TH of Ov.
PT was obtained.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram for explaining the structure of the semiconductor device of the present invention, Fig. 2 is an explanatory diagram schematically showing a circuit for measuring the characteristics of the semiconductor device of the present invention, and Fig. 6 , Figure 5,
6 and 7 are schematic explanatory diagrams for explaining examples of semiconductor film manufacturing apparatuses according to the present invention, respectively, and FIG. 4 is a schematic explanatory diagram for explaining steps for manufacturing a semiconductor element of the present invention. FIG. 8 is an explanatory diagram showing an example of the VD- characteristics of the semiconductor device of the present invention. 101...Substrate 102...Thin film semiconductor layer 106...Source electrode 10G...Drain electrode 105...Insulating layer 106...Gate electrode 107.108...♂ layer

Claims (1)

[Claims] 1. A semiconductor device characterized in that its main portion is constituted by a conductor layer in a polycrystalline silicon germanium thin film containing 5 atomic % or less of hydrogen atoms.